Method for measuring fluorescent light amount or light absorption amount and device for measuring the same

A method for measuring a fluorescent light amount, whereby a specimen is irradiated with excitation light, and fluorescent light generated from the specimen is measured by a light-receiving element via of a receiving optical system, the method includes the steps of irradiating the specimen with excitation light having a light-amount value per specified unit area traceable to the national standard, and designated on the surface of the specimen beforehand, causing the light-receiving element to measure the fluorescent light generated from the specimen, and computing a fluorescent light-amount as measured by the light-receiving element of the receiving optical system on the basis of an excitation light-amount per the specified unit area, optical coefficients of the receiving optical system, and the acceptance coefficient of the light-receiving element, thereby working out a light amount value per the unit area traceable to the national standard.